Natural Outbreaks Research Articles

Bringing horse genetics to owners and industry professionals through online extension

Equine herpesvirus type 1 (EHV-1)-induced myeloencephalopathy (EHM) is a neurologic disease of horses that represents one outcome of infection. The neurologic form of disease occurs in a subset of infected horses when virus-induced endothelial cell damage triggers vasculitis and subsequent ischemic insult to the central nervous system. EHM causes considerable animal suffering and economic loss for the horse industry. Virus polymorphisms have been previously associated with disease outcome but cannot fully explain why only some horses develop EHM. This study investigated the role of host genetics in EHM. DNA samples were collected from 129 horses infected with EHV-1 (61 that developed EHM and 68 in which disease resolved without the development of neurologic signs) during natural outbreaks or experimental infections. A genome-wide association study (GWAS) was performed to investigate host genetic variations associated with EHM. Genotyping was performed using the Illumina SNP50 and SNP70 arrays and a custom Sequenom array.Mixed linear model (MLM) analysis using a recessive model identified one marker that surpassed the threshold for genome-wide significance (P < 0.001) after Bonferroni correction. The marker (BIEC2_946397) is in an intron of the tetraspanin 9 (TSPAN9) gene, which is expressed in endothelial cells and platelets. The GWAS identified a region in the horse genome that is associated with EHM in the sample population and thus warrants further exploration. Understanding the contribution of host genetic variation to the development of EHM will enhance our knowledge of disease pathophysiology, and lead to improved strategies for treating individual cases and managing outbreaks.

Rainbow trout resistance to bacterial cold water disease: two new quantitative trait loci identified after a natural disease outbreak on a French farm.

In rainbow trout farming, Flavobacterium psychrophilum, the causative agent of bacterial cold water disease, is responsible for important economic losses. Resistance to F.psychrophilum is heritable, and several quantitative trait loci (QTL) with moderate effects have been detected, opening up promising perspectives for the genetic improvement of resistance. In most studies however, resistance to F.psychrophilum was assessed in experimental infectious challenges using injection as the infection route, which is not representative of natural infection. Indeed, injection bypasses external barriers, such as mucus and skin, that likely play a protective role against the infection. In this study, we aimed at describing the genetic architecture of the resistance to F.psychrophilum after a natural disease outbreak. In a 2000-fish cohort, reared on a French farm, 720 fish were sampled and genotyped using the medium-throughput Axiom™ Trout Genotyping Array. Overall mortality at the end of the outbreak was 25%. Genome-wide association studies were performed under two different models for time to death measured on 706 fish with validated genotypes for 30060 SNPs. This study confirms the polygenic inheritance of resistance to F.psychrophilum with a few QTL with moderate effects and a large polygenic background, the heritability of the trait being estimated at 0.34. Two new chromosome-wide significant QTL and three suggestive QTL were detected, each of them explaining between 1% and 4% of genetic variance.

Development and Evaluation of a Triplex TaqMan Assay and Next-Generation Sequence Analysis for Improved Detection of Xylella in Plant Material.

Xylella fastidiosa is a heterogenous gram-negative bacterial plant pathogen with a wide host range covering over 300 plant species. Since 2013, in Europe, the presence of the pathogen is increasing in a part of the Mediterranean area, but it causes in particular severe disease problems in olive orchards in the Southern part of Italy. Various subspecies of the pathogen were also diagnosed in natural outbreaks and intercepted ornamental plants in Europe, among them Olea europaea, Coffea arabica, and Nerium oleander. The host range of the pathogen can vary, depending on the subspecies and even the strain. The availability of fast and reliable diagnostic tools is indispensable in management strategies to control diseases caused by X. fastidiosa. To improve the reliability of the TaqMan assay, currently widely used in surveys, a triplex TaqMan assay was developed in which two specific and sensitive TaqMan assays, previously designed for X. fastidiosa, were combined with an internal control. The triplex assay exhibited the same diagnostic sensitivity as the simplex assays. In addition, the usefulness of a metagenomic approach using next-generation sequencing (NGS) was demonstrated, in which total DNA extracted from plant material was sequenced. DNA extracts from plant material free of X. fastidiosa, from artificially inoculated hosts plants or from naturally infected plants sampled in France, Spain, and Italy, or intercepted in Austria and the Netherlands, were analyzed for the presence of X. fastidiosa using the metagenomic approach. In all samples, even in samples with a low infection level, but not in the pathogen-free samples, DNA reads were detected specific for X. fastidiosa. In most cases, the pathogen could be identified to the subspecies level, and for one sample even the whole genome could be assembled and the sequence type could be determined. All results of NGS-analyzed samples were confirmed with the triplex TaqMan polymerase chain reaction and loop-mediated isothermal amplification.

Molecular characterization and pathogenicity of Francisella noatunensis subsp. orientalis isolated from cultured tilapia (Oreochromis sp.) in Taiwan

Francisella noatunensis subsp. orientalis is a causative agent of systemic granulomatous disease in tilapia. The present study was designed to understand the genetic and phenotypic diversities among Taiwanese Fno isolates obtained from tilapia (n=17) and green Texas cichlid (Herichthys cyanoguttatus) (n=1). The enzymatic profiles of the isolates were studied using the API ZYM system. Phylogenetic tree analysis of the 16S rRNA and housekeeping gene and pulsed-field gel electrophoresis (PFGE) were carried out to determine the genotypic characters of all isolates. The phylogenetic tree showed similarity of 99%-100% nucleotide sequences of 16S rRNA and housekeeping genes compared to the Fno references genes from GenBank database. Comparatively, the results revealed an identical profile of enzymatic and PFGE pattern which was distincted from that of F. philomiragia. To understand the pathogenicity, the isolates were intraperitoneal injected to tilapia the gross lesions were observed concomitant with natural outbreak. Median lethal dose upon Nile tilapia and red tilapia were 9.06 × 103 CFU/fish and 2.08 × 102 CFU/fish, respectively. Thus, our data provide understanding the epidemiology of Taiwanese Fno isolates, and help in development of future control and prevention.

Immunological Assay of Ukraine Viral Hemorrhagic Vaccine in Rabbits

This study aimed to establish immune level and protection of Ukraine vaccine against viral rabbit hemorrhagic disease (VRHD) and determine Histopathological changes among different affected ages. 10 random vaccinated adult breeding rabbits and 10 random unvaccinated weaned rabbit (5 from mother vaccinated at mid-pregnancy &5 from mother vaccinated at labor) were selected from a total of 200 rabbits (128 females, 40 males and 32 weaned) which vaccinated with Ukraine VRHDV (viral rabbit hemorrhagic disease vaccine) as seasonal vaccination routine work at 18/12/2017, blood samples were collected for obtaining their sera to determine HI titer at 16, 23, 30, 37 and 70 days post vaccination (dpv) in adult breeding rabbits, while collected from weaned rabbits at 45, 60 old age. This rabbit farm as a whole observed for natural outbreak through one year. Adult breeding rabbits showed HI titer of 240±23.851, 380±77.974, 480±47.703, 960±95.406 and 800±143.108 at 16, 23, 30, 37 and 70 dpv respectively while weaned rabbits from mother vaccinated at mid-pregnancy showed HI titer of 440±61.968 & 200±20.656 at 45 & 60 old age respectively also weaned rabbits from mother vaccinated at labor showed HI titer of 290±67.132 & 140±10.328 at 45 & 60 old age respectively. 1st Natural outbreak of RHD (rabbit hemorrhagic disease) occurred 5 months' post vaccination affecting non vaccinated weaned rabbits only, while 2nd Natural outbreak affecting both vaccinated and non-vaccinated rabbits at 9 months' post vaccination with severe mortalities. Histopathology of livers, kidneys, lungs and hearts were applied exhibiting hemorrhage, edema and inflammatory cells infiltrations in all organs with coagulative necrosis of liver and renal tubules accompanied by myocardial degeneration, these lesions varied in its severity and spreading according to affected ages. Finally, Ukraine VRHDV protect against RHD viral infection for a limited period which required to be determined in other studies.

Pathology and molecular characterization of pigeon paramyxovirus-1 from natural outbreaks in central India

Pathology and molecular characterization of pigeon paramyxovirus-1 from natural outbreaks in central India

Spatiotemporal patterns of historic animal Anthrax outbreaks in Minnesota and Kazakhstan

Event Abstract Back to Event Spatiotemporal patterns of historic animal Anthrax outbreaks in Minnesota and Kazakhstan Kaushi S. Kanankege1*, Sarsenbay Abdrakhmanov2 and Andres M. Perez1 1 University of Minnesota Twin Cities, United States 2 S. Seifullin Kazakh Agro Technical University, Kazakhstan The epidemiological triad recognizes the effect that the interaction between host, pathogen, and environment has on the resulting disease pattern in a population. Yet the influences of each triad component may dramatically vary for different conditions. For example, the recurrence of Anthrax in endemic areas is believed to be correlated with environmental characteristics, suggesting that comparable epidemiological patterns should be evidenced in regions with similar environmental conditions, despite differences in the demographic, socio-economic, and historical backgrounds. The objective here was to compare the spatiotemporal patterns of historic animal Anthrax records from two endemic sites that are located at a similar latitude but have been subjected to different demographic and socio-economic conditions. The spatiotemporal directionality test and scan statistics were used to compare between the sites. The spatiotemporal directionality tests and scan statistics were used to compare between the sites. Reported animal Anthrax cases in Minnesota, USA (n=289 cases between 1912-2014) and Kazakhstan (n=3,997 cases between 1933-2014) were analyzed. Epidemic curves indicated sporadic Anthrax outbreaks in Minnesota, whereas a long-term epidemic was detected in Kazakhstan. A comparable seasonality of the animal Anthrax cases was observed at both sites with a peak in August. The maximum time-span between cases at the same location were 55 and 60 years apart for Minnesota and Kazakhstan respectively. Disease hotspots were recognized in both settings, with spatially overlapping clusters years apart. Distribution of the spatiotemporal cluster radii between study sites supported the suggestion of site-specific control zones. Further studies are needed to investigate the association of trigger events that lead to the space-time specific Anthrax outbreaks at both the sites. Spatiotemporal patterns of Anthrax occurrence in both endemic regions were attributed to multiple potential trigger events including major river floods, changes in land use, agriculture, and susceptible livestock populations. Results here help to understand the long-term epidemiological dynamics of Anthrax while providing suggestions to the design and implementation of prevention and control programs, in endemic settings. Acknowledgements This study was funded in part by: 1) AMP: the Minnesota Discovery, Research, and Innovation Economy (MnDRIVE) program of the Office of the Vice President for Research (OVPR) of the University of Minnesota and 2) SKA: Scientific Thematic “Zonification of Kazakhstan according to biosecurity categories with regard to dangerous infectious animal diseases” under the Program #249 of funding scientific researches in agro-industry and environmental management by the Ministry of Agriculture of Kazakhstan References Kanankege KST, Abdrakhmanov SK, Alvarez J, Glaser L, Bender JB, Mukhanbetkaliyev YY, Korennoy FI, Kadyrov AS, Abdrakhmanova AS, Perez AM. Comparison of spatiotemporal patterns of historic natural Anthrax outbreaks in Minnesota and Kazakhstan. Plos One. 2019 May 17;14(5):e0217144. doi: 10.1371/journal.pone.0217144. eCollection 2019 Keywords: Anthrax, spatiotemperal model, Minnesota (USA), Kazakhstan, Cluster analisys Conference: GeoVet 2019. Novel spatio-temporal approaches in the era of Big Data, Davis, United States, 8 Oct - 10 Oct, 2019. Presentation Type: Regular oral presentation Topic: Spatio-temporal surveillance and modeling approaches Citation: Kanankege KS, Abdrakhmanov S and Perez AM (2019). Spatiotemporal patterns of historic animal Anthrax outbreaks in Minnesota and Kazakhstan. Front. Vet. Sci. Conference Abstract: GeoVet 2019. Novel spatio-temporal approaches in the era of Big Data. doi: 10.3389/conf.fvets.2019.05.00067 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Jun 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Kaushi S Kanankege, University of Minnesota Twin Cities, St. Paul, United States, kanan009@umn.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Kaushi S Kanankege Sarsenbay Abdrakhmanov Andres M Perez Google Kaushi S Kanankege Sarsenbay Abdrakhmanov Andres M Perez Google Scholar Kaushi S Kanankege Sarsenbay Abdrakhmanov Andres M Perez PubMed Kaushi S Kanankege Sarsenbay Abdrakhmanov Andres M Perez Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Role of Coxiella burnetii in the development of fever of unknown origin: А mini review

Q fever is a widespread zoonosis throughout the world in the form of numerous natural and agricul-tural outbreaks. C. burnetii infects various hosts, including humans, ruminants and pets and in rare cases, reptiles, birds, and ticks. This bacterium is excreted in urine, milk, faeces, and birth products. In humans Q fever occurs as acute or chronic disease with diverse clinical presentation, as isolated cases and epidemics. It affects various organs and systems, and in pregnant women can cause miscar-riage or premature birth. Untreated Q fever can become chronic with adverse effects on patients. Diversity in the clinical picture in the absence of specific pathological syndrome often hinders accurate diagnosis and proper etiological significance. Therefore, improvement of diagnostic methods and in particular the development and introduction of new molecular diagnostic methods is the basis of effective therapeutic and prophylactic approach. Тhe purpose of the review is to renew the interest to Q fever – on one hand, because of its serious impact on human health and agricultural systems, and on the other, the ability for development and introduction of new molecular diagnostic methods.

Natural outbreak of Marek's disease in indigenous chicken and Japanese quail (Coturnix coturnix japonica) in Jos, Plateau State, Nigeria.

Carcasses of an indigenous adult chicken and Japanese quail from different flocks were presented to a veterinary clinic for postmortem (PM) examination in 2014 in Jos, Plateau State, Nigeria. PM observations revealed cutaneous, hepatic, and splenic tumors in the Indigenous chicken. The quail carcass was emaciated with hepatic tumors. Histopathology revealed severe focally extensive non-encapsulated circumscribed large nodules with pleomorphic population of cells mainly composed of lymphoplasmacytic and mixed neutrophilic polymorphonuclear cells in the chicken. The pleomorphic infiltration of lymphohistioplasmacytic cells mixed with neutrophilic polymorphonuclear cells in the quail was consistent with Marek’s disease virus (MDV) infection. Polymerase chain reaction (PCR) was carried out, and the Meq oncogene of the MDV was amplified in the samples collected from the chicken and quail to confirm the presence of the virulent MDV. The samples were also subjected to PCR for detection of MDV Rispens CVI988 vaccine strain which was detected in both chicken and quail samples. The findings in this study represent the first report of confirmatory diagnosis of MD using histopathology in an indigenous chicken and Japanese quail in Nigeria. It is also the first report of the detection of MDV Rispens CVI988 vaccine strain in unvaccinated chicken and quail in Nigeria.

Recalibration of the Grunow-Finke Assessment Tool to Improve Performance in Detecting Unnatural Epidemics.

Successful identification of unnatural epidemics relies on a sensitive risk assessment tool designed for the differentiation between unnatural and natural epidemics. The Grunow-Finke tool (GFT), which has been the most widely used, however, has low sensitivity in such differentiation. We aimed to recalibrate the GFT and improve the performance in detection of unnatural epidemics. The comparator was the original GFT and its application in 11 historical outbreaks, including eight confirmed unnatural outbreaks and three natural outbreaks. Three steps were involved: (i) removing criteria, (ii) changing weighting factors, and (iii) adding and refining criteria. We created a series of alternative models to examine the changes on the parameter likelihood of unnatural outbreaks until we found a model that correctly identified all the unnatural outbreaks and natural ones. Finally, the recalibrated GFT was tested and validated with data from an unnatural and natural outbreak, respectively. A total of 238 models were tested. Through the removal of criteria, increasing or decreasing weighting factors of other criteria, adding a new criterion titled "special insights," and setting a new threshold for likelihood, we increased the sensitivity of the GFT from 38% to 100%, and retained the specificity at 100% in detecting unnatural epidemics. Using test data from an unnatural and a natural outbreak, the recalibrated GFT correctly classified their etiology. The recalibrated GFT could be integrated into routine outbreak investigation by public health institutions and agencies responsible for biosecurity.

Genome-wide association study of equine herpesvirus type 1-induced myeloencephalopathy identifies a significant single nucleotide polymorphism in a platelet-related gene

Equine herpesvirus type 1 (EHV-1)-induced myeloencephalopathy (EHM) is a neurologic disease of horses that represents one outcome of infection. The neurologic form of disease occurs in a subset of infected horses when virus-induced endothelial cell damage triggers vasculitis and subsequent ischemic insult to the central nervous system. EHM causes considerable animal suffering and economic loss for the horse industry. Virus polymorphisms have been previously associated with disease outcome but cannot fully explain why only some horses develop EHM. This study investigated the role of host genetics in EHM. DNA samples were collected from 129 horses infected with EHV-1 (61 that developed EHM and 68 in which disease resolved without the development of neurologic signs) during natural outbreaks or experimental infections. A genome-wide association study (GWAS) was performed to investigate host genetic variations associated with EHM. Genotyping was performed using the Illumina SNP50 and SNP70 arrays and a custom Sequenom array.Mixed linear model (MLM) analysis using a recessive model identified one marker that surpassed the threshold for genome-wide significance (P<0.001) after Bonferroni correction. The marker (BIEC2_946397) is in an intron of the tetraspanin 9 (TSPAN9) gene, which is expressed in endothelial cells and platelets. The GWAS identified a region in the horse genome that is associated with EHM in the sample population and thus warrants further exploration. Understanding the contribution of host genetic variation to the development of EHM will enhance our knowledge of disease pathophysiology, and lead to improved strategies for treating individual cases and managing outbreaks.

Pathogenicity and Full Genome Sequencing of the Avian Influenza H9N2 Moroccan Isolate 2016.

In Morocco in early 2016, a low pathogenic avian influenza virus serotype H9N2 caused large economic losses to the poultry industry, with specific clinical symptoms and high mortality rates on infected farms. Subsequent to the H9N2 outbreak, the causal agent was successfully isolated from chicken flocks with high morbidity and mortality rates, propagated on embryonated eggs, and fully sequenced. The phylogenetic analysis suggested that the Moroccan isolate could have derived from the Middle East isolate A/chicken/Dubai/D2506.A/2015. This study was designed to assess the pathogenicity of the Moroccan isolate H9N2 in experimentally infected broiler and specific-pathogen-free (SPF) chickens. At 22 days of age, one broiler and two SPF chicken groups were inoculated by dropping 0.2 ml of the H9N2 isolate (107.5 EID50/ml) in both nostrils and eyes. Clinically inoculated chickens with H9N2 displayed mild lesions, low mortality rates, and an absence of clinical signs. The H9N2 virus was more pathogenic in broiler chickens and produced more severe tissue lesions compared to SPF chickens. The viral shedding was detected up to 6 days postinoculation (pi) in oropharyngeal and cloacal swabs in infected birds with a maximum shedding in the oropharynges of the broiler group. All experimental chickens seroconverted and registered high hemagglutination inhibition titers as early as day 7 pi. The present study indicates that the H9N2 virus isolated from a natural outbreak was of low pathogenicity under experimental conditions. However, under field conditions infection with other pathogens might have aggravated the disease.

Detection and quantification of a keystone pathogen in a coastal marine ecosystem

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 606:79-90 (2018) - DOI: https://doi.org/10.3354/meps12776 Detection and quantification of a keystone pathogen in a coastal marine ecosystem Robyn Buchwald, Robert E. Scheibling*, Alastair G. B. Simpson Department of Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada *Corresponding author: rescheib@dal.ca ABSTRACT: The pathogenic amoeba Paramoeba invadens causes recurrent mass mortalities of green sea urchins Strongylocentrotus droebachiensis in coastal Nova Scotia, Canada, driving regime shifts from urchin barrens to kelp beds. Outbreaks of the disease (paramoebiasis) are sporadic, and the source population(s) and epizootiology of the amoeba are poorly understood. We developed PCR-based detection of P. invadens in urchin tissue, sediment, and seawater. Primers specific to the P. invadens nuclear SSU rRNA gene were designed and used in PCR and qPCR analyses to better detect and quantify P. invadens during, following, and in the absence of a natural disease outbreak. A comparison of pathogen load in asymptomatic and symptomatic sea urchins indicated a lower threshold of ~1 cell mg-1 tissue for observing overt signs of paramoebiasis in urchins. P. invadens was detected for the first time in sediment during and following an outbreak of disease in 2014. It also was detected in low abundance (<10 cells l-1) in seawater in fall 2015 in the absence of sea urchin mass mortality or a strong storm event, but not under similar conditions in summer/fall 2016 and 2017. The ability to detect and quantify this pathogen in sea urchins and environmental samples sheds new light on mechanisms of introduction, spread, and persistence of P. invadens along the Nova Scotian coast and the role of large-scale meteorological events and ocean warming in these processes. KEY WORDS: Epizootic · Ecosystem dynamics · Paramoeba invadens · Strongylocentrotus droebachiensis · Quantitative real-time PCR · Pathogenic amoebae · Sea urchins Full text in pdf format Supplementary material PreviousNextCite this article as: Buchwald R, Scheibling RE, Simpson AGB (2018) Detection and quantification of a keystone pathogen in a coastal marine ecosystem. Mar Ecol Prog Ser 606:79-90. https://doi.org/10.3354/meps12776 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 606. Online publication date: November 15, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.

Subspecies differentiation and genotyping of Francisella tularensis strains isolated from clinical and environmental samples.

Molecular epidemiology is one of the most rapidly developing research area. In the light of past and modern technologies it has gained number of typing methods based on molecular biology techniques. In this report, the subspecies differentiation of Francisella tularensis and genotyping of strains isolated in Poland and other geographic locations were investigated using real-time PCR and multispacer typing (MST) methods respectively. In total, 49 strains of F.tularensis included 15 strains from Poland, for subspecies differentiation the real-time PCR method was applied. For molecular typing using MST method four intergenic spacers (IS) were sequenced and compared with those previously described and deposited in GenBank (NCBI). Phylogenetic testing was performed using with the UPGMA model using MEGA6 software. The real-time PCR enables to distinguish five strains belonged to type A and 44 to type B among deposited F.tularensis strains. The MST revealed previously described genotypes, as well as 23 new genotypes were detected. The use of real-time PCR and MST method are valuable in the analysis of F.tularensis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrate convenient molecular tools (real-time PCR and multispacer typing) for Francisella tularensis detection, differentiation and genotyping which can be applied for molecular epidemiological studies and providing useful information for scientific research and during natural tularaemia outbreaks.

Pathology of experimentally induced mouthrot caused by Tenacibaculum maritimum in Atlantic salmon smolts.

Mouthrot, caused by Tenacibaculum maritimum is a significant disease of farmed Atlantic salmon, Salmo salar on the West Coast of North America. Smolts recently transferred into saltwater are the most susceptible and affected fish die with little internal or external clinical signs other than the characteristic small (usually < 5 mm) yellow plaques that are present inside the mouth. The mechanism by which these smolts die is unknown. This study investigated the microscopic pathology (histology and scanning electron microscopy) of bath infected smolts with Western Canadian T. maritimum isolates TmarCan15-1, TmarCan16-1 and TmarCan16-5 and compared the findings to what is seen in a natural outbreak of mouthrot. A real-time RT-PCR assay based on the outer membrane protein A specific for T. maritimum was designed and used to investigate the tissue tropism of the bacteria. The results from this showed that T. maritimum is detectable internally by real-time RT-PCR. This combined with the fact that the bacteria can be isolated from the kidney suggests that T. maritimum becomes systemic. The pathology in the infected smolts is primarily mouth lesions, including damaged tissues surrounding the teeth; the disease is similar to periodontal disease in mammals. The pathological changes are focal, severe, and occur very rapidly with little associated inflammation. Skin lesions are more common in experimentally infected smolts than in natural outbreaks, but this could be an artefact of the challenge dose, handling and tank used during the experiments.

Global Bioheroes: clinical research and new vaccines for health security

ABSTRACTIn the pursuit of ‘global health security’, some governments advocate deployment of pharmaceuticals to combat deadly infectious diseases wherever they emerge. Following the Ebola outbreak in West Africa, attention has turned to other emerging diseases and future pharmaceutical solutions. There is growing support for enabling faster clinical research to make new vaccines available sooner. Research on experimental vaccines must ordinarily be consistent with ethical principles designed to protect human research participants. However, where a target disease is framed in security terms, it could be argued that an extraordinary response is required: exposing research participants to more risk in order to accelerate research and enable more lives to be saved pharmaceutically. This article assesses two scenarios of security-oriented research. The scenario envisaged by the Coalition for Epidemic Preparedness Innovations (CEPI) is the propelling of vaccine research through to the stage of human safety-testing before a natural outbreak of the relevant disease. Efficacy and effectiveness tests are then able to be conducted once an outbreak begins. In a hypothetical second scenario, pre-outbreak vaccine research undertaken for the sake of health security would also include efficacy-testing. This would involve the exposure to pathogenic microorganisms of healthy volunteers (‘global bioheroes’) from around the world.

Expression of infection-related immune response in European sea bass (Dicentrarchus labrax) during a natural outbreak from a unique dinoflagellate Amyloodinium ocellatum

In the Mediterranean area, amyloodiniosis represents a major hindrance for marine aquaculture, causing high mortalities in lagoon-type based rearing sites during warm seasons. Amyloodinium ocellatum (AO) is the most common and important dinoflagellate parasitizing fish, and is one of the few fish parasites that can infest several fish species living within its ecological range. In the present study, A. ocellatum was recorded and collected from infected European sea bass (Dicentrarchus labrax) during a summer 2017 outbreak in north east Italy. Histological observation of infected ESB gill samples emphasized the presence of round or pear-shaped trophonts anchored to the oro-pharingeal cavity. Molecular analysis for small subunit (SSU) rDNA of A. ocellatum from gill genomic DNA amplified consistently and yielded 248 bp specific amplicon of A. ocellatum, that was also confirmed using sequencing and NCBI Blast analysis. Histological sections of ESB gill samples were addressed to immunohistochemical procedure for the labelling of ESB igm, inos, tlr2, tlr4, pcna and cytokeratin. Infected gills resulted positive for igm, inos, pcna and cytokeratin but negative to tlr-2 and tlr-4. Furthermore, ESB immune related gene response (innate immunity, adaptive immunity, and stress) in the course of A. ocellatum infection using quantitative polymerase chain reaction (qpcr) for infected gills and head kidney was analysed. Among the twenty three immune related gene molecules tested, cc1, il-8, il-10, hep, cox-2, cla, cat, casp9, and igt were significantly expressed in diseased fish. Altogether, these data on parasite identification and expression of host immune-related genes will allow for a better understanding of immune response in European sea bass against A. ocellatum and could promote the development of effective control measures.

Acinetobacter lwoffii, an emerging pathogen for fish in Schizothorax genus in China.

Acinetobacter lwoffii, a serious human pathogen, has been identified as a cause of nosocomial infections such as bacteremia, pneumonia and meningitis. There are only a few studies reporting A.lwoffii as a pathogen of fish. During 2016 and 2017, six bacterial strains, isolated from diseased fish of the Schizothorax genus, were identified as A.lwoffii by morphology, biochemical tests, 16S rDNA and gyrB gene sequencing analysis. One of these isolates was selected for experimental infection of Sclizothorax prenanti, Schizothorax davidi and Schizothorax wangchiachii, to confirm its pathogenicity. Experimentally infected fish showed similar symptoms to those observed in fish after natural outbreaks. Susceptibility of the isolates to 14 antibiotics was tested using a disc diffusion method; all isolates were resistant to cephalothin, aminoglycosides and β-lactams, and sensitive only to some fluoroquinolones and tetracyclines. Histological examination revealed that A.lwoffii infection could cause pathological lesions in multiple organs and tissues, especially in liver, kidney, spleen and heart. These lesions included extensive haemorrhage, vacuolar degeneration, necrosis and inflammatory cell infiltration. To our knowledge, this is the first report on A.lwoffii as a virulent pathogen for fish of the Schizothorax genus.

Nipah virus in India: past, present and future

Nipah virus (NiV) is one of the emerging highly pathogenic virus. Like Ebola and Zika viruses, NiV too is threatening the integrity of the mankind. The family Paramyxoviruses has been traditionally associated with a group of viruses with narrow host range and typically causes outbreaks with low mortality rates. But with the emergence of highly pathogenic Hendra virus and closely related NiV, they have evolved as a cause of fatal encephalitis across broad range of vertebrate species including humans. The natural reservoir of NiV is Pteropus bat, which is apparently distributed all over the South East Asia. The bat population from North East to North West states in India have NiV antibodies which mean there is active NiV infection among Indian bats. As NiV is associated with high morbidity and mortality they pose a risk from natural outbreaks, laboratory accidents or deliberate misuse. The development of effective prevention and treatment strategies is very crucial. Preparedness, surveillance, constant vigil needs to be carried out continuously in the country. The present outbreak in India after nearly eleven years with a high case fatality rate indicate that there is a total lack of health care systems preparedness and surveillance strategy. The anthropogenic and environmental changes occurring due to rapid urbanization and massive deforestation has made India now even more vulnerable for such recurrent outbreaks. This review highlights the changing trend of the NiV outbreaks in the past and the current outbreak in India.

Isolation characterization, virulence potential of Weissella ceti responsible for weissellosis outbreak in rainbow trout (Oncorhynchus mykiss) cultured in Mexico.

Weissella ceti, a Gram-positive nonmotile bacterium, is currently an emerging pathogen within rainbow trout (Oncorhynchus mykiss) farms in China, Brazil, the United States, and Japan. This study is the first to isolate, identify, and characterize W.ceti isolates from rainbow trout farmed in Mexico. In late 2015, a severe disease outbreak caused a 60% mortality rate among 20,000 fish. The diseased rainbow trout (100-300g average) exhibited severe cachexia, body darkening, abdominal distension, exophthalmia, haemorrhages, and corneal opacity. Internally, diseased fish had pale gills; multifocal, disseminated whitish spots on the liver; haemorrhages in the swim bladder, ovary, and on the parietal surface of the muscle; and hearts with pseudo-membrane formation. Histologically, lesions were characterized by corneal oedema, degenerative and necrotic hepatitis, and meningitis. A brain (W-1) and kidney (W-2) isolate were identified as W.ceti through polyphasic taxonomy, which included phenotypic characterization and 16S rRNA sequencing. RAPD and ERIC-PCR analyses demonstrated genetic homogeneity among the Mexican isolates. Virulence tests in rainbow trout through intraperitoneal W.ceti injections at concentrations of 1×104 , 1×105 , and 1×106 CFU per fish resulted in cumulative mortality rates of 25%, 62.5%, and 87.5%, respectively, as well as the same clinical signs of hemorrhagic septicaemia as were recorded for the natural outbreak. The present report is the first to confirm the presence of W.ceti in Mexico, thus extending the known geographical distribution of this pathogen across the Americas.